Thermal break type architectural extrusions

ABSTRACT

Metal extrusions adapted for use in building constructions including a rigid spacer member capable of forming a thermal break. The extrusions comprise spaced apart structural members having a unique web member spanning the space between the structural members. The web member extends convexly between the structural members thereby providing an ideal surface for use in aligning the extrusions during processing. The extrusions also include flange members which with the structural members and the web member define a cavity within which the rigid spacer member of low thermal conductivity is constrained. A process of forming the extrusions is also claimed.

United States Patent [191 Weinstein [451 July 16, 1974 THERMAL BREAKTYPE ARCHITECTURAL EXTRUSIONS [75] Inventor: Paul Weinstein,Wallingford, Conn.

[73] Assignee: Swiss Aluminum Ltd., Chippis,

Switzerland 22 Filed: Jan. 12,1973

21 Appl.No.:323,149

[52] US. Cl. 52/729, 29/155 R, 52/309, 52/403 [51] Int. Cl... E04c 3/29[58] Field of Search 52/730, 732, 402, 403, 52/481, 309, 729; 29/155 R[56] References Cited UNITED STATES PATENTS 2 1945 Sheldon 52/481 2/1957Kunkel..... 52/400 X 9/1965 Nilsen 29/155 R 5/1969 Revell et al. 29/155R Bragman 52/732 X Holiday et all 29/155 R Primary ExaminerAlfred C.Perham Attorney, Agent, or Firm-R. H. Bachman [5 7] ABSTRACT Metalextrusions adapted for use in building constructions including a rigidspacer member capable of forming a thermal break. The extrusionscomprise spaced apart structural members having a unique web memberspanning the space between the structural members. The web memberextends convexly between the structural members thereby providing anideal surface for use in aligning the extrusions during processing. Theextrusions also include flange members which 7 with the structuralmembers and the web member define a cavity within which the rigid spacermember of low thermal conductivity is constrained. A process of formingthe extrusions is also claimed.

' 20 Claims, 6 Drawing Figures THERMAL BREAK TYPE ARCHITECTURALEXTRUSIONS BACKGROUND OF THE INVENTION This invention relates to metalextrusions adapted for use in building constructions such as windows,doors, and curtain wall. The extrusions of this invention include arigid spacer member of relatively low thermal conductivity which canprovide a thermal break between the inside and outside of the building.The invention also includes a process for making the extrusions.

US. Pat. No. 3,204,324, granted Sept. 7, 1965, and US. Pat. No.3,624,885, granted Dec. 7, I971, deal with extrusions in the samegeneral field as those of this invention. The extrusions of thisinvention, however, represent a marked improvement over those disclosedby the patents.

In accordance with the patents, there are disclosed extrusionsincorporating a rigid spacer member for forming a thermal break. Theextrusions in accordance with this invention incorporate a design whichpennits the elimination of the projections required by the designs ofthe patents and which further provides a selfaligning feature whichmakes it easier to align the extrusion during processing and therebysimplify the fixturing and jigging required.

SUMMARY OF THE INVENTION In accordance with this invention, there areprovided metal extrusions adapted for use in building constructions suchas doors, windows, and curtain wall. The extrusion comprises first andsecond structural members positioned in adjacent spaced-apart relation,a flange member projecting outwardly from each of the structural membersin the space between the structural members, a web member spanning thespace between the structural members while being spaced apart from theflange members and rigidly joining the structural members together. Theweb member in accordance with this invention has a unique design wherebyit extends convexly between the structural members in such a way thatthe space between the web member and the flange members decreases thefurther out the web member projects from each of the structural members.

A cavity is defined by the structural members, the web member, and theflange members; and a rigid spacer member of relatively low thermalconductivity is provided within the cavity.

In accordance with another embodiment of the invention, a slot isprovided in the web member which separates the structural members toprovide a thermal break. In this latter embodiment, the structuralmembers are held together in rigid engagement by the spacer member, anda complete thermal break is provided between the structural members.

Preferably in accordance with this invention, the web member has asubstantially V shaped cross section; and in accordance with a stillmore preferred embodiment, the flange members project outwardly from thestructural members and are inclined with respect to the structuralmembers so as to form a bow tie" like cavity. The unique shape of theWeb member, particularly in the embodiment where it has a substantiallyV" shaped cross section, provides an ideal surface for use in guidingthe extrusions during processing, such as when the extrusions are beingfilled with the spacer material or when the slot is being machined inthe web member.

The shape of the web member in accordance with this invention provides aself-alignment feature which substantially reduces the complexity of theapparatuses required to carry out the aforenoted processes. A stillfurther improvement is provided by the fact that the extrusions may beguided and aligned during processing without the necessity of contactingthe faces of the extrusion which are to be exposed to view, therebyeliminating potential causes of marring of the finish of these surfaces.

Accordingly, it is an object of this invention to provide metalextrusions for use in building constructions such as windows, doors, andcurtain wall.

It is a further object of this invention to provide extrusions as aboveincluding a web member having a configuration which is adapted toprovide for selfalignment of the extrusion during processing.

It is a further object of this invention to provide extrusions as aboveincluding a rigid spacer member of relatively low thermal conductivitywhich can provide a thermal break.

It is a further object of this invention to provide extrusions as abovewherein a slot is provided in the web member to provide a completethermal break.

It is another object of this invention to provide a process for formingthe extrusions of this invention wherein the extrusions are aligned forprocessing, such as filling the cavity with spacer material, by engagingthe web member with a suitable aligning device.

Other objects and advantages will become apparent to those skilled inthe art as a detailed discussion of particular embodiments proceeds withreference to the drawings which form a part hereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross section of anextrusion in accordance with one embodiment of this invention.

FIG. 2 shows a crosssection of an extrusion in accordance with apreferred embodiment of this invention.

accordance with yet another embodiment of this invention.

FIG. 6 is a perspectiveview showing an extrusion in accordance with yetanother embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1,there is shown a cross section of an extrusion l in accordance with oneembodiment of this invention. The extrusion 1 comprises first and secondstructural members 2 and 3 which are positioned in adjacent spaced-apartrelation. Flange members 4 project outwardly from each of the structuralmembers 2 and 3 in the space between the structural members 2 and 3 witheach of the flange members 4 having a free edge 5. A web member 6 spansthe space between the structural members 2 and 3. The web member 6 isspaced apart from the flange members 4 and rigidly joins together thestructural members 2 and 3.

In accordance with a unique feature of the extrusion of this invention,the web member 6 extends convexly between the structural members 2 and 3so that the space between the web member 6 and the flange members 4decreases the further out the web member 6 projects from each of thestructural members 2 and 3.

A cavity 7 is defined by the structural members 2 and 3, the web member6, and the flange members 4. A rigid spacer member 8 of relatively lowthermal conductivity is constrained within the cavity 7. The spacermember 8 substantially fills up the cavity 7 to provide arigid jointbetween the structural members 2 and 3 when a slot 9 as in FIG. 3 isformed in the web member 6 to provide a complete thermal break.

In the embodiment of FIG. 1, the flange members 4 extend out from thestructural members 2 and 3 in a direction generally normal to the faces10 of the structural members 2 and 3.

In accordance with other preferred embodiments of the invention as shownin FIGS. 2, 5, and 6, the flange members 4 may extend out from thestructural mem bers at an angle with respect to the faces I of thestructural members 2 and 3, the flange members 4 being angled in such away that they extend outwardly from the structural members 2 and 3 andtoward the web member 6.

The combination of the inclined flange members 4 and the V shaped webmember 6 form a bow tie like cavity 7. Further, referring to FIG. 2, itis possible to provide integral overflow lips 11 coextensive with theedges of the flanges 4 so as to make it easier to completely fill thecavity 7 without spilling spacer material on other portions of theextrusion I.

Referring again to FIG. 1, the web member 6 is convexly disposed betweenthe spaced-apart structural members 2 and 3. The web member 6 shownextends out from each of the structural members 2 and 3 at an angle tothe faces thereof in a direction toward the flange members 4. A flatportion 12 of the web member 6 extends generally normal to thestructural members. This normally extending portion 12 of the web member6 is approximately the width of the slot 9 which will eventually beformed in the web member 6 to provide the thermal break. The web member6 in FIG. I, therefore, has a generally V" shaped cross-section with aflat 12 at the vertex of the .V.

In accordance with this invention, the web member 6 may have any desiredconvex shape which is adapted to provide the self-aligning and locatingfeature which will be described in more detail with reference to FIG. 5later. The web member 6 shown in FIG. I, however, is one of thepreferred embodiments since it provides self-alignment of the extrusion1 during the spacer 8 material filling operation and during the slot 9machining operation. With respect to the slot 9 machining operation, theuse of a flat 12 as in FIG. 1 provides for uniform metal removal therebymaking the web member 6 easier to machine. The sloped sides 13 of the V-shaped web member 6 provide the self-aligning feature, since the cutter24 as in FIG. 6 contacting the web member 6 as in FIG. 1 will slide downthe sloped sides 13 to the flat.

In the extrusion of FIG. 2, the web member 6 is completely V shaped andthe flat 12 has been eliminated. This configuration is also a preferredembodiment in accordance with this invention and provides excellentself-locating and aligning properties for the web member 6.

FIG. 3 shows the extrusion l of FIG. 1 after the slot 9 has beenmachined in the web member 6 so as to provide a complete thermal breakbetween the structural members 2 and 3. After the slot 9 has been formedin the web member 6, the web member 6 becomes two portions 14 inopposing relationship to the flange members 4. The rigid spacer member 8joins the structural members 2 and 3 together in a rigid fashion. Theconvexity of the web member portions 14 or the slope of the portions 14as shown in FIG. 3 effectively locks the spacer member 8 to each of thestructural members 2 and 3. This results from the fact that the webportions 14 extend out from each of the structural members 2 and 3 at anangle with respect to the faces 10. The web portions 14 are angled insuch a way that they extend outwardly from the structural members 2 and3 and toward the flange members 4.

FIG. 3 shows a typical portion of a building construction, namely anextrusion l in accordance with this invention, engaging a panel 15 whichmight be employed in a curtain wall. Weather strips 16 are providedwhich are secured to the structural members 2 and 3 by means of theslots 17 and which resiliently engage the panel 15.

FIG. 4 shows the most preferred configuration of the extrusion l inaccordance with this invention wherein the flange members 4 project outfrom the structural members 2 and 3 at an angle with respect to thefaces 10 and in a direction toward the web portions 14. The

. web member 6 in FIG. 2 has been slotted .to provide the web portions14 in the extrusion I of FIG. 4. The extrusion I of FIG. 4 is preferredbecause the engagement of the flange members 4 in addition to theengagement of the web portions 14 provides a superior locking actionbetween the thermally insulating spacer member 8 and the structural.members 2 and 3.

The cavity 7 of the extrusion l of FIG. 2 and the resulting spacermember 8 in the construction of FIG. 4 have a bow tie like shape whichis very effective in preventing the structural members 2 and 3 frompulling apart from each other and provides a very strong rigid jointbetween the structural members 2 and 3. The extrusion l of FIG. 4 isshown engaged with a glass window pane 18 in a manner similar to theengagement with the panel shown in FIG. 3. Resilient sealing gaskets 6are secured to the extrusion l by means of the slot 17 and resilientlyengage the window 18.

From the discussion of FIGS. 1 through 4, it is clear that thisinvention deals with two types of extrusions l. The first type, asexemplified by the extrusions of FIGS. 1 and 2, includes a web member 6spanning the gap between the structural members 2 and 3 which rigidlyjoins the structural members 2 and 3 together. The extrusions l in thisform are most useful for production purposes, since the desired windowshapes, door shapes, or curtain wall shapes can be fabricated withoutdamaging the spacer member 8.

In accordance with the embodiment of FIGS. 3 and 4, an extrusion l isprovided wherein the web member 6 has been separated into portions 14with a slot 9 in between. This represents the desired form of theextrusion 1 after fabrication has been accomplished and a thermal breakstructure is desired. These extrusions are essentially similar to thoseof FIGS. 1 and 2 with the exception that the web member 6 has beenslotted to form spaced apart portions 14 and thereby provide a completethermal break between the structural members 2 and 3 of the extrusion 1.

Since the inclination of the web portions 14 or of the web portions 14and the flange members 4 provide a bow tie like structure whicheffectively joins the structural members 2 and 3 to the rigid spacermember 8 in accordance with this invention, the projections required bythe prior art to keep the structural members 2 and 3 from pulling aparthave been eliminated without the loss of their function.

The self-locating and alignment feature of the extrusion 1 in accordancewith this invention is clearly shown in FIG. 5. FIG. 5 shows anextrusion 1 similar to the design of FIGS. 2 and 4, but without theoptional overflow lips 11 along the free edges 5 of the flanges 4. Asshown in FIG. 5, a guide wheel 19 or other means for aligning theextrusion l with a dispensing nozzle 20 is provided. The guide wheel 19in the illustration engages the web member 6 and has a V shaped contourwhich mates with the V shaped contour of the web member 6. While onlyone guide wheel 19 is shown, it is obvious that the apparatus forcarrying out this process should probably include a plurality of suchwheels 19.

A roller 21 is provided in opposing relationship to the guide wheel 19and engages the edges 22 of the struc-,

tural members 2 and 3 so as to push the web member 6 against the guidewheel 19. Therefore, it is readily evident that the convex shape of theweb members 6 of the extrusions l of this invention provide a relativelyeasy means for locating the extrusions 1 and aligning the extrusions 1during processing. Further, since the locating means 19 does not contactthe faces 10 of the structural members 2 and 3 which are visible whenthe extrusions are in use, there is a much lesser tendency for thesefaces I0 to be marred or damaged during processing.

The extrusion 1 shown in FIG. 5 is a further altema: tive embodiment inaccordance with this invention and includes a further feature not yetdiscussed, namely the extrusion 1, includes a plurality of holes 23 inthe flanges 4 which are small enough to prevent the spacer 8 materialfrom easily flowing out of them, but large enough to allow for some flowof the spacer 8 material into them. The advantage of this constructionis that it provides means for preventing the structural members 2 and 3from moving longitudinally with respect to one another in addition topreventing them from being pulled apart.

Referring now to FIG. 6, an extrusion 1 similar to that of FIG. 5without the holes 23 is shown. The extrusion 1 is in the process ofhaving the slot 9 machined in the web member 6 to provide the separateweb portions 14 and the complete thermal break. It is readily evidentthat the V" shape of the web member 6 provides a similar type ofself-alignment with the cutter 24 during the machining operation,thereby reducing the fixturing necessary to carry out the machining andthe chances of marring or damaging the extrusion 1.

The process in accordance with this invention comprises providing anextrusion 1 including first 2 and second 3 structural members positionedin adjacent spaced apart relation, a flange member 4 projectingoutwardly from each of the structural members 2 and 3 in the spacebetween the structural members 2 and 3 and a web member 6 spanning thespace between the structural members 2 and 3 while being spaced apartfrom the flange members 4 and rigidly joining the structural members 2and 3 together. The web member 6 extends convexly between the structuralmembers 2 and 3 in such a way that the space between the web member 6and the flange members 4 decreases the further out the web member 6projects from each of structural members 2 and 3. The extrusion 1further includes a cavity 7 defined by the structural members 2 and 3,the web member 6 and the flange members 4.

The extrusion 1 thus provided is aligned under a suitable dispensingmeans 20 for dispensing a spacer material of relatively low thermalconductivity into the cavity 7. The alignment is accomplished byengaging the concave side of the web member 6 with a suitable means 19for aligning the extrusion l as in FIG. 5. The dispensing means 20 maycomprise a nozzle as in FIG. 5 or any other suitable type of device.Conventional grouting or caulking equipment can be used for thispurpose. After the extrusion 1 has been aligned beneath dispensing means20 spacer material having a relatively low thermal conductivity isdispensed so that it flows into and fills the cavity 7. The flowing andfilling of the cavity may be facilitated by the use of vibration.

The spacer material of relatively low thermal conductivity may be anydesired insulating material used for such purposes in the art. In thepreferred embodiment of this invention the insulating spacer material isformed of a resinous material and may also include fillers and/or fibersthat are selected for the strength as well as the insulating propertiesthey impart. The insulating spacer material is compounded to havetensile strength, dimensional stability, resistance to impact, moistureand sub-freezing temperatures as required by the particularinstallation. Preferably, the insulating spacer material should exhibitgood adhesion to the metal of the extrusion I. In the case of thisinvention the extrusions 1 may be made of any desired metal such asaluminum, aluminum alloys, copper, copper alloys and other metals foundin similar applications. This adhesion property is not an' essentialaspect of this invention.

After the cavity has been filled with the spacer material of low thermalconductivity the spacer material is allowed to solidify, as for example,by curing of a resinous composition to harden it and thereby provide arigid spacer member 8 joined to each of the structural members 2 and 3.The processing may further include the step of machining a slot 9 in theweb member 6 to separate it into separate portions 14 and therebyprovide a complete thermal break. The machining may be accomplished bythe use of a milling cutter 24 as shown in FIG. 6 or by sawing or theuse of a cut-off wheel or any other desired means.

To provide an extrusion in accordance with FIG. 5, it is necessary priorto the step of machining the slot 9 that the holes 23 or perforations beformed in the flange members 4. This may be accomplished by anyconventional technique such as punching or drilling or by such exotictechniques such as laser or electron beam machining.

The extrusions 1 provided in the process of the present invention mayhave any desired structure such as the preferred structures illustratedin FIGS. ll through 6. In accordance with this invention the structuralmembers 2 and 3 may have planar faces as shown in FIGS. 1 through 6 orthey may have any desired configuration or sectional shape as arewell-known in the art. For example, one or both of the structuralmembers 2 and 3 may comprise a plurality of pieces in interlockingengagement. The extrusions l illustrated in FIGS. 1 through 6 are merelyexemplary and are not meant to be limited of the invention.

The extrusions 1 are adaptable to a large number of constructions andare particularly adaptable for use in configurations such as frames forsupporting edges of windows or panels.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiment is therefore to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of equivalency are intended to be embracedtherein.

What is claimed is:

l. A metal extrusion adapted for use in building constructions, saidextrusion consisting essentially of:

first and second structural members positioned in adjacent spaced-apartrelation;

a flange member projecting outwardly from each of said structuralmembers in said space between said structural members, each of saidflange members having a free edge;

a web member spanning the space between said structural members. saidweb member being spaced apart from said flange members and rigidlyjoining together said structural members, said web member extendingconvexly between said structural members so that the space between saidweb member and said flange members decreases as said web member projectsout from each of said structural members;

a cavity defined by said structural members, said web member, and saidflange members;

a rigid spacer member of relatively low thermal conductivity constrainedwithin said cavity.

2. A metal extrusion as in claim 1 wherein said flange members areangled with respect to said structural members so that they extendoutwardly from the structural members and toward the web members.

3. An extrusion in accordance with claim 1 wherein each flange memberhas an integral overflow lip along its free edge, said overflow lipsbeing coextensive with said flange members.

4. A metal extrusion as in claim 1 wherein said web member has asubstantially V shaped cross-section.

5. A metal extrusion as in claim 4 wherein a flat is present at thevertex of said V" shaped web member.

6. An extrusion as in claim 2 wherein said web member has asubstantially V shaped cross-section whereby said cavity has a bow tielike shape.

7. An extrusion as in claim 3 wherein said web member has asubstantially V shaped cross-section whereby said cavity has a bow tielike shape.

8. An extrusion as in claim 1 wherein said flange members have aplurality of holes.

9. A metal extrusion adapted for use in building constructions saidextrusion consisting essentially of:

first and second structural members positioned in adjacent spaced apartrelation;

a flange member projecting outwardly from each of said structuralmembers, in said space between said structural members, each of saidflange members having a free edge;

web portions projecting outwardly from each of said structural membersin said space between said structural members said web portionsextending towards said flange members and being spaced apart from saidflange members, said web portions defining a slot;

a cavity defined by said structural members, said web portions and saidflange members;

a rigid spacer member of relatively low thermal conductivity constrainedwithin said cavity and rigidly joining together said structural members.

10. A metal extrusion as in claim 9 wherein said flange members areangled with respect to said structural members so that they extendoutwardly from the structural members and toward the web portions.

11. An extrusion in accordance with claim 9 wherein each flange memberhas an integral overflow lip along its free edge, said overflow lipsbeing coextensive with said flange members.

12. An extrusion as in claim 2 wherein said cavity has a bowtie likeshape.

13. An extrusion as in claim 9 wherein said flange members have aplurality of holes.

14. An extrusion as in claim 10 wherein said flange members have aplurality of holes.

15. A process of forming a metal extrusion adapted for use in buildingconstructions said process comprismg:

providing a metal extrusion consisting essentially of first and secondstructural members positioned in adjacent spaced-apart relation, aflangemember projecting outwardly from each of the structural members inthe space between the structural members each of the flange membershaving a free edge, a web member spanning the space between thestructural members, the web member being spaced apart from the flangemembers and rigidly joining together the structural members, the webmember extending convexly between the structural members so that thespace between the web member and flange members decreases as the webmember projects out from each of the structural members and a cavitydefined by the structural members, the web member and the flangemembers;

aligning said extrusion with a means for dispensing a solidifiablespacer material of low thermal conductivity into said cavity, byengaging said convexly extending web member with means for aligning saidextrusion;

filling said cavity with said solidifiable spacer material from saiddispensing means; and

solidifying said spacer material to form a rigid spacer memberconstrained within said cavity.

16. A process as in claim wherein said spacer material comprises aresinous insulating material and wherein said solidification stepcomprises the step of curing said resinous material to harden it.

17. A process as in claim 15 further including the step of perforatingsaid flange members prior to said alignment step to provide a pluralityof holes therein.

18. A process as in claim 15 further including the said resinousmaterial to harden it.

1. A metal extrusion adapted for use in building constructions, saidextrusion consisting essentially of: first and second structural memberspositioned in adjacent spaced-apart relation; a flange member projectingoutwardly from each of said structural members in said space betweensaid structural members, each of said flange members having a free edge;a web member spanning the space between said structural members, saidweb member being spaced apart from said flange members and rigidlyjoining together said structural members, said web member extendingconvexly between said structural members so that the space between saidweb member and said flange members decreases as said web member projectsout from each of said structural members; a cavity defined by saidstructural members, said web member, and said flange members; a rigidspacer member of relatively low thermal conductivity constrained withinsaid cavity.
 2. A metal extrusion as in claim 1 wherein said flangemembers are angled with respect to said structural members so that theyextend outwardly from the structural members and toward the web members.3. An extrusion in accordance with claim 1 wherein each flange memberhas an integral overflow lip along its free edge, said overflow lipsbeing coextensive with said flange members.
 4. A metal extrusion as inclaim 1 wherein said web member has a substantially ''''V'''' shapedcross-section.
 5. A metal extruSion as in claim 4 wherein a flat ispresent at the vertex of said ''''V'''' shaped web member.
 6. Anextrusion as in claim 2 wherein said web member has a substantially''''V'''' shaped cross-section whereby said cavity has a ''''bow tie''''like shape.
 7. An extrusion as in claim 3 wherein said web member has asubstantially ''''V'''' shaped cross-section whereby said cavity has a''''bow tie'''' like shape.
 8. An extrusion as in claim 1 wherein saidflange members have a plurality of holes.
 9. A metal extrusion adaptedfor use in building constructions said extrusion consisting essentiallyof: first and second structural members positioned in adjacent spacedapart relation; a flange member projecting outwardly from each of saidstructural members, in said space between said structural members, eachof said flange members having a free edge; web portions projectingoutwardly from each of said structural members in said space betweensaid structural members said web portions extending towards said flangemembers and being spaced apart from said flange members, said webportions defining a slot; a cavity defined by said structural members,said web portions and said flange members; a rigid spacer member ofrelatively low thermal conductivity constrained within said cavity andrigidly joining together said structural members.
 10. A metal extrusionas in claim 9 wherein said flange members are angled with respect tosaid structural members so that they extend outwardly from thestructural members and toward the web portions.
 11. An extrusion inaccordance with claim 9 wherein each flange member has an integraloverflow lip along its free edge, said overflow lips being coextensivewith said flange members.
 12. An extrusion as in claim 2 wherein saidcavity has a ''''bowtie'''' like shape.
 13. An extrusion as in claim 9wherein said flange members have a plurality of holes.
 14. An extrusionas in claim 10 wherein said flange members have a plurality of holes.15. A process of forming a metal extrusion adapted for use in buildingconstructions said process comprising: providing a metal extrusionconsisting essentially of first and second structural members positionedin adjacent spaced-apart relation, a flange member projecting outwardlyfrom each of the structural members in the space between the structuralmembers each of the flange members having a free edge, a web memberspanning the space between the structural members, the web member beingspaced apart from the flange members and rigidly joining together thestructural members, the web member extending convexly between thestructural members so that the space between the web member and flangemembers decreases as the web member projects out from each of thestructural members and a cavity defined by the structural members, theweb member and the flange members; aligning said extrusion with a meansfor dispensing a solidifiable spacer material of low thermalconductivity into said cavity, by engaging said convexly extending webmember with means for aligning said extrusion; filling said cavity withsaid solidifiable spacer material from said dispensing means; andsolidifying said spacer material to form a rigid spacer memberconstrained within said cavity.
 16. A process as in claim 15 whereinsaid spacer material comprises a resinous insulating material andwherein said solidification step comprises the step of curing saidresinous material to harden it.
 17. A process as in claim 15 furtherincluding the step of perforating said flange members prior to saidalignment step to provide a plurality of holes therein.
 18. A process asin claim 15 further including the step of machining a longitudinallyextending slot in said web member.
 19. A process as in claim 18 whereinsaid machining is carried out by milling.
 20. A process as in claim 19wherein said solidifiable spacer material comprises a resinousinsulating material and saiD solidifying step comprises the curing ofsaid resinous material to harden it.